71 research outputs found
Coherent optical ultrasound detection with rare-earth ion dopants
No full textWe describe theoretical and experimental demonstration for optical detection of ultrasound using a spectral hole engraved in cryogenically cooled rare-earth ion-doped solids. Our method utilizes the dispersion effects due to the spectral hole to perform phase-to-amplitude modulation conversion. Like previous approaches using spectral holes, it has the advantage of detection with large étendue. The method also has the benefit that high sensitivity can be obtained with moderate absorption contrast for the spectral holes.</p
Experimental realization of light with time-separated correlations by rephasing amplified spontaneous emission
No full textAmplified spontaneous emission is a common noise source in active optical systems, it is generally seen as being an incoherent process. Here we excite an ensemble of rare earth ion dopants in a solid with a π pulse, resulting in amplified spontaneous emission. The application of a second π pulse leads to a coherent echo of the amplified spontaneous emission that is correlated in both amplitude and phase. For small optical thicknesses, we see evidence that the amplified spontaneous emission and its echo are entangled.</p
Spectral-hole memory for light at the single-photon level
No full textWe demonstrate a solid-state spin-wave optical memory based on stopped light in a spectral hole. A long-lived narrow spectral hole is created by optical pumping in the inhomogeneous absorption profile of a Pr3+:Y2SiO5 crystal. Optical pulses sent through the spectral hole experience a strong reduction of their group velocity and are spatially compressed in the crystal. A short Raman pulse transfers the optical excitation to the spin state before the light pulse exits the crystal, effectively stopping the light. After a controllable delay, a second Raman pulse is sent, which leads to the emission of the stored photons. We reach storage and retrieval efficiencies for bright pulses of up to 39% in a 5-mm-long crystal. We also show that our device works at the single-photon level by storing and retrieving 3-μs-long weak coherent pulses with efficiencies up to 31%, demonstrating the most efficient spin-wave solid-state optical memory at the single-photon level so far. We reach an unconditional noise level of (9±1)×10-3 photons per pulse in a detection window of 4μs, leading to a signal-to-noise ratio of 33±4 for an average input photon number of 1, making our device promising for long-lived storage of nonclassical light.Fil: Kutluer, Kutlu. Barcelona Institute of Technology; EspañaFil: Pascual Winter, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Dajczgewand, Julian Eduardo. Université Paris Sud; Francia. Centre National de la Recherche Scientifique; FranciaFil: Ledingham, Patrick M.. Barcelona Institute of Technology; EspañaFil: Mazzera, Margherita. Barcelona Institute of Technology; EspañaFil: Chanelière, Thierry. Université Paris Sud; Francia. Centre National de la Recherche Scientifique; FranciaFil: De Riedmatten, Hugues. Barcelona Institute of Technology; Españ
Quantum storage of a photonic polarization qubit in a solid
No full textWe report on the quantum storage and retrieval of photonic polarization quantum bits onto and out of a solid state storage device. The qubits are implemented with weak coherent states at the single photon level, and are stored for a predetermined time of 500 ns in a praseodymium doped crystal with a storage and retrieval efficiency of 10%, using the atomic frequency comb scheme. We characterize the storage by using quantum state tomography, and find that the average conditional fidelity of the retrieved qubits exceeds 95% for a mean photon number μ=0.4. This is significantly higher than a classical benchmark, taking into account the Poissonian statistics and finite memory efficiency, which proves that our crystal functions as a quantum storage device for polarization qubits. These results extend the storage capabilities of solid state quantum light matter interfaces to polarization encoding, which is widely used in quantum information science.</p
Quantum storage of a photonic polarization qubit in a doped crystal
No full textWe report storage of photonic polarization qubits in a crystal. The average conditional fidelity of retrieved qubits exceeds 95% for a mean photon number μ = 0.4, higher than the classical benchmark proving the quantum nature of the storage.</p
Hybrid optical and electronic laser locking using slow light due to spectral holes
No full textWe report on a narrow linewidth laser diode system that is stabilized using both optical and electronic feedback to a spectral hole in cryogenic Tm:YAG. The large group delay of the spectral hole leads to a laser with very low phase noise. The laser has proved useful for quantum optics and sensing applications involving cryogenic rare-earth-ion dopants.</p
Quantum Correlations between Single Telecom Photons and a Multimode On-Demand Solid-State Quantum Memory
No full textQuantum correlations between long-lived quantum memories and telecom photons that can propagate with low loss in optical fibers are an essential resource for the realization of large-scale quantum information networks. Significant progress has been realized in this direction with atomic and solid-state systems. Here, we demonstrate quantum correlations between a telecom photon and a multimode on-demand solid state quantum memory. This is achieved by mapping a correlated single photon onto a spin collective excitation in a Pr^{3+}:Y_{2}SiO_{5} crystal for a controllable time. The stored single photons are generated by cavity-enhanced spontaneous parametric down-conversion and heralded by their partner photons at telecom wavelength. These results represent the first demonstration of a multimode on-demand solid state quantum memory for external quantum states of light. They provide an important resource for quantum repeaters and pave the way for the implementation of quantum information networks with distant solid state quantum nodes
Storage of up-converted telecom photons in a doped crystal
No full textWe report on an experiment that demonstrates the frequency up-conversion of telecommunication wavelength single-photon-level pulses to be resonant with a Pr3+:Y2SiO5 crystal. We convert the telecom photons at 1570 nm to 606 nm using a periodically-poled potassium titanyl phosphate nonlinear waveguide. The maximum device efficiency (which includes all optical loss) is inferred to be ηmaxdev = 22 ± 1% (internal efficiency ηint = 75 ± 8%) with a signal to noise ratio exceeding 1 for single-photon-level pulses with durations of up to 560 ns. The converted light is then stored in the crystal using the atomic frequency comb scheme with storage and retrieval efficiencies exceeding ηAFC = 20% for predetermined storage times of up to 5 μs. The retrieved light is time delayed from the noisy conversion process allowing us to measure a signal to noise ratio exceeding 100 with telecom single-photon-level inputs. These results represent the first demonstration of single-photon-level optical storage interfaced with frequency up-conversion.</p
Nonclassical photon streams using rephased amplified spontaneous emission
No full textWe present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission; however, this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an "echo" of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwith quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas
Solid State Spin-Wave Quantum Memory for Time-Bin Qubits
No full textWe demonstrate the first solid-state spin-wave optical quantum memory with on-demand read-out.
Using the full atomic frequency comb scheme in a Pr3þ∶Y2SiO5 crystal, we store weak coherent pulses at
the single-photon level with a signal-to-noise ratio > 10. Narrow-band spectral filtering based on spectral
hole burning in a second Pr3þ∶Y2SiO5 crystal is used to filter out the excess noise created by control pulses
to reach an unconditional noise level of ð2.0 0.3Þ × 10−3 photons per pulse. We also report spin-wave
storage of photonic time-bin qubits with conditional fidelities higher than achievable by a measure and
prepare strategy, demonstrating that the spin-wave memory operates in the quantum regime. This makes
our device the first demonstration of a quantum memory for time-bin qubits, with on-demand read-out
of the stored quantum information. These results represent an important step for the use of solid-state
quantum memories in scalable quantum networks.Peer ReviewedPostprint (published version
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